Production verifyReceipt endpoint declined using Cloudflare

I am trying to do a POST request to the verifyReceipt production endpoint using Cloudflare Workers. I intentionally stripped out all the receipt data, so the expected output would be status 21002 (The data in the receipt-data property was malformed).

const url = ""

addEventListener("fetch", event => {
  return event.respondWith(handleRequest())

async function handleRequest(request)
  const init = {
    method: "POST"

  const response = await fetch(url, init)
  const results = await response.text()
  return new Response(results, init)

Using the sandbox url (, this is working fine! However, when switching it out for the production endpoint it suddenly results in status 21199 (internal data access errors).

Even when doing the request within the Cloudflare Workers test environment, it works, but when deploying the worker, it does not. Also, executing the request from other servers works as desired - the issue is specifically related with requests coming from Cloudflare.

Does Apple have any measures active to decline Cloudflare Workers requests on this production endpoint? Is there a way around it?